To study the influence of organizational climate on unsafe behavior of construction workers, the organizational climate was measured from three aspects including the team level safety climate, the team level safety education and the project level safety climate, then the occurrence mechanism of construction workers' unsafe behavior was constructed based on the relationship of organizational climate with safety attitude, unsafe motivation and safety capacity. Through collecting the data of 267 valid questionnaires from more than 20 projects, the verification was carried out by using the structural equation model (SEM), and the influence degree and influenced degree among the latent variables were further calculated and analyzed by using the decision-making trial and evaluation laboratory (DEMATEL). The results showed that the influence of team level safety climate on safety attitude, team level safety education on safety attitude, safety capacity on safety attitude and safety attitude on safety motivation were significant, and the influence of safety motivation and safety capacity on unsafe behavior were significant. The correlation among the team level safety climate, the team level safety education and the project level safety climate was significant. The team level safety climate, the team level safety education and the project level safety education were the typical cause influence factors, and influenced the unsafe behavior together through the safety attitude. The countermeasures were put forward according to the research results, which can provide the theoretical guide to safety management work.